Belong to. Commodity price difference, referred to as "price difference", refers to the futures price difference of different grades, different delivery months, different commodities and different delivery places. Earning price difference refers to the price difference between buying goods and selling goods. Merchants are mainly profitable. Earning the difference is the essence of a businessman, so earning the difference belongs to the businessman. The reasons for the price difference are very complicated, such as: different geographical environment, different supply and demand relationship, different labor prices, different cultures and so on.